Riveting apparatus

ABSTRACT

A pneumatically operated blind riveting apparatus includes an elongate mandrel having a stem and a head at the forward end thereof, and two pairs of alternately operable jaws associated with the mandrel, each of which serves to hold the mandrel when the other pair is open. One of the pairs of jaws constitutes an abutment for supporting a tubular blind rivet during a setting operation while the other pair of jaws is located rearwardly of the abutment jaws and is movable longitudinally of the mandrel whereupon, when in the closed position, such jaws may pull the mandrel head rearwardly through a rivet supported by the abutment jaws and may also return the mandrel forwardly. A jet delivers a blast of gas so as to propel rivets from the rear end of the mandrel towards the head past each of the pairs of jaws.

United States Patent [1 1 Charman Sept. 3, 1974 RIVETING APPARATUS Primary Examiner -Charles W. Lanham 7 I Assistant Examiner-Gene P. Crosby t ll h I [75] [men or gg g Attorney, Agent, or Firm-Oblon, Fisher, Spivak,

McClelland & Maier [73] Assignee: Aerpat A.G., Zug, Switzerland 22 Filed: Ma 26, 1972 [571 T C v A pneumatically operated blind riveting apparatus in- [21] Appl 'f 257244 eludes an elongate mandrel having a stem and a head- 1 at the forward end thereof, and two pairs of alter- [30] Foreign Application Priority Data nately operable jaws associated with the mandrel, Ma 28, 1971 Great Britain 18177/71 each of which serves the mandrel when the other pair is open. One of the pairs of jaws constitutes 52 us. ca. 72/391 abutment for Supporting a tubular blind rivet 51 Int. Cl B21j 15/34 ing a Setting Operation While the other P o l is [58] Field of Search 72/391, 424; 227/55; located rearwardly of the ahuhmm jaws and is 29/243 53 able longitudinally of the mandrel whereupon, when in v the closed position, such jaws may pull the mandrel [5 f en Cited head rearwardly through a rivet supported by the UNITED STATES PATENTS abutment jaws and may also return the mandrel, forwardly. A jet delivers a blast of gas so as to propel rivigx' ets from the rear end ofthe mandrel towards the head 3:717:023 2/1973 Presser 72 391 past each Ofthe P a 5 Claims, 6 Drawing Figures PATENT'EDSEP3 1914 v vSHEET 2 OF 2 1 RIVETING APPARATUS This invention relates to blind riveting apparatus for setting blind tubular rivets of the kind comprising a shank and an enlarged head at one end of the shank, and having a bore extending through the head and shank. Such rivets are well known and are commercially available under the registered Trade Mark Chobert.

More particularly the invention relates to blind riveting apparatus which is adapted to supply blind tubular rivets to a setting station, and to set the rivets at the setting station.

According to the present invention, there is provided blind riveting apparatus, comprising anelongated mandrel having an enlarged head and a stem extending rearwardly of the head, holding means for holding the mandrel and providing an abutment for supporting a rivet in a rivet setting operation, axially reciprocable gripping means for gripping the mandrel at a position rearwardly of the holding means and for moving the mandrel axially relative to the abutment to pull the enlarged head through a tubular rivet supported by the I rearward position (as shown in FIG. 1), and a forward position (as shown in FIG. 4). In FIG. 1, where the abutment, the holding means and the gripping means each being operable to release the mandrel when the other of the holding and gripping means is holding the mandrel, to allow a rivet to move forwardly along the The means for advancing a rivet along the mandrel may comprise means for directing a jet of gas forwardly onto a rivet positioned on the mandrel axis.

One form of the invention will now be described with reference to the accompanying diagrammatic drawings in which: i

FIG. 1 is a schematic elevation, partly in section, showing the principal parts of a riveting machine and a riveted workpiece, the machine having just set a rivet in the workpiece;

FIGS. 2, 3 and 4, are schematic elevations, partly in section, similar to FIG; 1 but showing the positions of the principal parts of the machine in further stages of operation and FIGS. 5 and 6 are fragmentary elevation and plan views, respectively, of parts of the machine.

The machine of this embodiment is adapted to set blind tubular rivets in a workpiece at a setting station from a position below the workpiece.

mandrel is at its rearward position, the head 16 of the mandrel is disposed between the nose-jaws 18, 20'

which have moved resiliently apart to allow the enlarged head of the mandrel to enter between them. As

a forward position (as shown in FIG. 4) and, in their rearward position, are movable between a closed position in which they co-operate to grip the mandrel as shown in FIG. 1, and an open position in which they are disengaged from the mandrel as shown in FIG. 2.

Each of the gripping jaws 26, 28 is provided with four gripping fingers which are arranged to interdigitate with the four gripping fingers of the outer gripping jaw, two of the gripping fingers 42, 44 being vertically spaced one above the other on one side of the mandrel stem and diverging from the other two gripping fingers 46 (of which only one isshown) which are also vertically spaced one above'the other on the other-side of the mandrel stem, the gripping fingers of the two gripping jaws being arranged to interdig'itate leaving a rectangular space between them in which the stem of the mandrel is gripped. The gripping jaws are poweroperated to move between their open and closed positions by means of pneumatically operated piston cylinder arrangements as shown schematically at 26a and 28a, and are reciprocable in their closed condition in a direction lengthwise of the mandrel by means of a pneumatic The riveting machine comprises a mandrel 12 having an elongated stem 14 and a head 16 at one end of the stem. The stem 14 is cylindrical, and the head 16 is of circular cross-section and tapers towards the stem so as to provide a conical surface 17. The head end of the mandrel is regarded as the forward end, the other end being the rear end of the mandrel. The mandrel is reciprocable along its axis in relation to a pair of nose-. jaws l8 and 20 which are arranged on opposite sides of the mandrel at a position adjacent to the head 16. The nose-jaws 18, 20 each present a forwardly facing abutment surface 22, 24 respectively. The nose-jaws are resilientlyv urged towards each other by springs shownschematically at 18a and 20a so as to close about the mandrel. In the closed position. of the nose-jaws, the abutment surfaces 22, 24 co-operate to form a substantially annular abutment peripherally of the mandrel.

jack as shown schematically at 26b and 28b A rivet feeding means 30 is disposed at a position which is rearwardly of thegripping jaws when the jaws are in their rearward position and is arranged to feed rivets successively into a position in which their bores are aligned with the mandrel axis and their tail ends are directed towards the head of the mandrel.

A jet 32 is arranged on the. axis of the mandrel at a position which is to the rear of the rear end of the mandrel when the mandrel is in its rearward position, and is arranged to deliver a blast of gas under pressure, such as compressed air, forwardly along'the stern of the mandrel. F I

The operation of the machine will now be described. Referring first to FIG. 1, in which the mandrel is in its rearward position, the gripping jaws have just pulled the-mandrel rearwardly and have thereby drawn the head of the mandrel through the bore of a rivet 40 and set the rivet in the aperturedworkpiece 38. It will be seen that the rear end of the mandrel has entered thebore of a rivet 34 which has previously been located in line with the mandrel axis by the feeding means 30. As

previously indicated, the nose-jaws 18, 20 are resil drel which continues to be held by the nose-jaws, and

simultaneously a blast of compressed air is delivered through the jet 3 2 forwardly along the. mandrel. The

' blast of air propels the rivet 34 forwardly along the stem of the mandrel, past the open gripping jaws, until are opened against the biasing action of springs 18a,

20a, by means of the pneumatic cylinder mechanisms schematically shown at 1817 and 2017, allowing the rivet 34 to be driven forwardly past the nose-jaws by the sustained blast of compressed air until the rivet abuts the rearward end of the head 16 of the mandrel.

As soon as the rivet 34 has passed forwardly of thev nose-jaws, actuation of the cylinder mechanisms 18b, 20b is terminated and the nose-jaws close under the influence of springs 18a, 20a so as to provide the substantially annular abutment rearwardly of the head of the rivet 34 and the blast of compressed air is cut off.

Due to the forward movement of the mandrel, its rear end is now spaced substantially forwardly of the feeding means 30 thus making room for a further rivet 36 which is fed by the feeding means to assume a position aligned with the mandrel axis.

The machine is now in a condition ready to be actuated to set the rivet 34.-An apertured workpiece. may now therefore be positioned so that the head of the mandrel and the'shankof the rivet 34 extend through the workpiece and so that the lower surface of the workpiece abuts the head of the rivet 34. On actuating the machine to set the rivet 34, the gripping jaws move rearwardly, pulling the mandrel rearwardly so as to draw the head 16 through the bore of the rivet 34 to set the rivet 34. As the mandrel moves rearwardly, the rear end of the mandrel stem enters into the bore of the further rivet 36. The machine thus reaches again the condition shown in FIG. 1 and the sequence of operations previously described is carried out to advance the rivet 36 forwardly along the mandrel to the position occupied by the rivet 34 in FIG. 4.

In the foregoing embodiment, the machine is operated entirely by pneumatic power using pneumatic piston/cylinder arrangements to translate the power into linear movement of jaws, but it will be appreciated that, instead of using pneumatic means for effecting the reciprocation of the gripping jaws and the opening and closing movements of the gripping jaws and the nosejaws, other means'such as rotating'or sliding cams or electrically powered actuators could be used. The ways and means tO achieve the required movements of the parts of the machine in appropriately timed relationship are well understood in the arts and form no part of the present invention.

It will be appreciated that the timing of the movements of the gripping jaws and the nose-jaws and of the delivery of a blast of gas from the jet to propel a rivet along the mandrel stem need not be exactly 'as described above since minor variations in the precise timing can be effected without impairing the essential mode of operation of the machine as hereinbefore defined.

I- claim:

1. Blind riveting apparatus, comprising an elongated mandrel having an enlarged head and a stem extending rearwardly of the head, holding means for holding the mandrel and providing an abutment for supporting a rivet in a rivet setting operation, axially reciprocable means for gripping the mandrel at a position rearwardly of the holding means and for moving the mandrel axially relative to the abutment to pull the enlarged head through a tubular rivet supported by the abutment, the

holding means and the gripping means each being operable to release the mandrel when the other of the holding and gripping means is holding the mandrel, to allow a rivet to move forwardly along the mandrel past the gripping means and the holding means, and means for advancing forwardly along the mandrel past the gripping means and the holding means a rivet supplied to the rearward end of the mandrel.

2. Blind riveting apparatus according to claim 1, wherein themeans for advancing a rivet forwardly along the mandrel comprises means for directing a blast of gas forwardly on to a-rivet positioned on the mandrel axis.

3. Blind riveting apparatus according to claim 1, wherein the gripping means comprises a pair of pneumatically operated gripping jaws.

4. Blind riveting apparatus according to claim 3, wherein the gripping jaws have interdigitating gripping fingers for gripping the mandrel.

5. Blind riveting apparatus according to claim 1, wherein the holding means comprises a pair of power operated jaws which, when closed, co-operate to hold the mandrel and to provide the abutment. 

1. Blind riveting apparatus, comprising an elongated mandrel having an enlarged head and a stem extending rearwardly of the head, holding means for holding the mandrel and providing an abutment for supporting a rivet in a rivet setting operation, axially reciprocable means for gripping the mandrel at a position rearwardly of the holding means and for moving the mandrel axially relative to the abutment to pull the enlarged head through a tubular rivet supported by the abutment, the holding means and the gripping means each being operable to release the mandrel when the other of the holding and gripping means is holding the mandrel, to allow a rivet to move forwardly along the mandrel pasT the gripping means and the holding means, and means for advancing forwardly along the mandrel past the gripping means and the holding means a rivet supplied to the rearward end of the mandrel.
 2. Blind riveting apparatus according to claim 1, wherein the means for advancing a rivet forwardly along the mandrel comprises means for directing a blast of gas forwardly on to a rivet positioned on the mandrel axis.
 3. Blind riveting apparatus according to claim 1, wherein the gripping means comprises a pair of pneumatically operated gripping jaws.
 4. Blind riveting apparatus according to claim 3, wherein the gripping jaws have interdigitating gripping fingers for gripping the mandrel.
 5. Blind riveting apparatus according to claim 1, wherein the holding means comprises a pair of power operated jaws which, when closed, co-operate to hold the mandrel and to provide the abutment. 